The present invention generally relates to automotive fuel pumps, and more particularly to a regenerative turbine type rotary impeller.
Regenerative fuel pumps that have an impeller with a ring extending around the outer diameter have been widely used in automotive applications because of their robust manufacturing, low cost, and high efficiency. These features are emphasized in low voltage, high pressure applications. However, this impeller design exhibits xe2x80x9cdisadvantageousxe2x80x9d characteristics when used in an Electrical Returnless Fuel System (ERFS). When the vehicle is at idle, the fuel pump of an ERFS typically spins at approximately 3,000 to 4,000 revolutions per minute (rpm), while the fuel pump of a traditional system spins at approximately 8,000-9,000 rpm. At the lower rpm rate, the impeller exhibits pressure pulsation noise in the fuel pump.
Therefore, there is a need for a fuel pump having an impeller which dampens the pressure pulsation within the fuel pump while maintaining the efficiency advantages of the ring impeller.